TY - GEN
T1 - On-line routing of real-time messages
AU - Leung, Joseph Y.T.
AU - Tam, Tommy W.
AU - Young, Gilbert H.
N1 - Funding Information:
1Research supported in part by ONR Grant N00014-87-K-0833 and in part by a grant from Texas Instruments, Inc.
Funding Information:
2Research supported by CUHK Grant 220500610. Gilbert Young is with Department of Computer Science & Engineering, the Chinese University of Hong Kong, Shatin, Hong Kong.
PY - 1990
Y1 - 1990
N2 - The problem of routing unit-length, real-time messages in a distributed system is considered. An on-line routing algorithm is a distributed algorithm that routes messages without any knowledge of future arrivals of messages. An on-line algorithm is optimal if it produces a feasible routing whenever one exists. In this paper we study the issue of whether it is possible to have an optimal on-line algorithm for the following networks-unidirectional ring, out-tree, in-tree, bidirectional tree and bidirectional ring. The problem is considered under various restrictions of the four parameters-origin node, destination node, release time and deadline. For unidirectional ring, it is shown that no such algorithm can exist unless one of the four parameters is fixed. For out-tree, we show that no such algorithm can exist unless one of the following three parameters-origin node, destination node and release time-is fixed. For in-tree, we show that no such algorithm can exist unless one of the following three parameters-origin node, destination node and deadline-is fixed. For bidirectional tree, it is shown that no such algorithm can exist unless either the origin node or the destination node is fixed. Finally, for bidirectional ring, we show that no such algorithm can exist unless the origin node and either the destination node or the release time are fixed.
AB - The problem of routing unit-length, real-time messages in a distributed system is considered. An on-line routing algorithm is a distributed algorithm that routes messages without any knowledge of future arrivals of messages. An on-line algorithm is optimal if it produces a feasible routing whenever one exists. In this paper we study the issue of whether it is possible to have an optimal on-line algorithm for the following networks-unidirectional ring, out-tree, in-tree, bidirectional tree and bidirectional ring. The problem is considered under various restrictions of the four parameters-origin node, destination node, release time and deadline. For unidirectional ring, it is shown that no such algorithm can exist unless one of the four parameters is fixed. For out-tree, we show that no such algorithm can exist unless one of the following three parameters-origin node, destination node and release time-is fixed. For in-tree, we show that no such algorithm can exist unless one of the following three parameters-origin node, destination node and deadline-is fixed. For bidirectional tree, it is shown that no such algorithm can exist unless either the origin node or the destination node is fixed. Finally, for bidirectional ring, we show that no such algorithm can exist unless the origin node and either the destination node or the release time are fixed.
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U2 - 10.1109/REAL.1990.128738
DO - 10.1109/REAL.1990.128738
M3 - Conference contribution
AN - SCOPUS:0011397393
SN - 0818621125
SN - 9780818621123
T3 - Proceedings - Real-Time Systems Symposium
SP - 126
EP - 135
BT - 1990 Proceedings 11th Real-Time Systems Symposium, RTSS 1990
T2 - 1990 11th Real-Time Systems Symposium, RTSS 1990
Y2 - 5 December 1990 through 7 December 1990
ER -